This invention relates to drivers for rotary surgical cutting tools, and, more particularly, to drivers used in maxillo-facial, neuro, dental and orthopedic surgery, including reamer drivers.
Screwdrivers, ratchet drivers, and other hand-held tools are often utilized to insert, remove and/or adjust fasteners attached to various items. The tool is used to rotate the fasteners into or out of apertures in the items to properly position the fasteners with respect to the items. In ratchet drivers, the rotation is controlled such that there is relatively free rotation in one direction and driven, locked rotation in the opposite direction.
Such tools include a coupling device which retains an insert used to drive the fastener or other item. With regards to ratchet tools, users have differing preferences and adhere to varying conventions as to what constitutes intuitive actuation of a mechanism. Because of this, manufacturers must provide different models which, for example, provide the user with a selection of operation that suits his preferences. For example, focus group studies have shown that some users intuitively associate a pushing action with engaging a tool to an insert. Among these users, a significant portion believes that the same action should also enable disengagement of the insert for insertion of a new insert. At the same time, other users polled associate a pulling action to engagement. Among these users, the same action should also enable disengagement of the insert for insertion of the new insert. The remaining believes that a combination of pushing and pulling should engage and/or disengage the insert. Because the prior art ratcheting mechanisms generally include a large number of parts assembled within the housing in order to complete the ratcheting and actuation mechanisms, a large inventory of the differing parts necessary to provide the user with the engagement/disengagement action they intuitively prefer. The complexity of these mechanisms increase the time and expense necessary for manufacturing tools incorporating these prior art ratcheting mechanisms. One significant expense is the inventory expense, which requires that there be sufficient sets of replacement parts to support each model. Another drawback is that as the number of parts which are similar in appearance (but not function) increases, the risk of misassembly or malassembly increases. Such misassembly could cause a component or assembly to disassemble in a patient's body cavity during surgery.
Therefore, what is needed is a simpler mechanism with fewer parts of simpler form. Still further, what is needed is a coupling device design which is configurable to the needs of the user, while minimizing the number of parts the manufacturer must inventory. Still further, what is needed is a coupling device that may be reconfigured for differing actuation without the need for replacing components with new, custom components. What is needed is a means for minimizing the number of parts a reseller or manufacturer must inventory without sacrificing the range of configurations he is able to assemble.